1. Field of the Invention
The present invention relates to a cabinet structure for a magnetic tape recorder, and particularly to such a cabinet structure capable of providing a shielding effect.
2. Related Arts
The magnetic tape recorder is sensitive to exterior noise signals of high-frequency, such as electromagnetic wave produced by radio sets or hair dryers used in the vicinity of the magnetic tape recorder, allowing noise signals to appear in the pictures and sound reproduced on the screen. The cylinder unit installed in the deck of the magnetic tape recorder is very sensitive to such noise signals no matter how weak they may be in strength, causing a disturbance in reproduced pictures and sound.
To prevent such a disturbance the cylinder unit is equipped with a shield plate. FIG. 4 shows a conventional deck structure having a cylinder unit and surrounding electronics and electric parts enclosed with a relatively large shield plate xe2x80x9caxe2x80x9d. FIG. 5 shows another conventional deck structure in which: a shield plate xe2x80x9cbxe2x80x9d put behind a cylinder unit xe2x80x9ccxe2x80x9d; and another shield plated xe2x80x9cdxe2x80x9d is placed to protect some parts other than the cylinder unit. In both of such conventional deck structures the cylinder unit is located so remote from the rear plate of the cabinet that noise signals can hardly reach the cylinder unit.
Incidentally the deck of the magnetic tape recorder is grounded to the cabinet, which makes up one part of the electronic circuit. To make sure of the grounding it is necessary that the deck be connected to the cabinet with metal or springs. This requires an extra work.
In view of the above one object of the present invention is to provide a cabinet structure for a magnetic tape recorder, which makes it unnecessary to use extra shield plates and grounding means.
To attain this object a cabinet structure for a magnetic tape recorder according to the present invention comprises a rear-and-bottom structure to which the deck of the magnetic tape recorder is to be fixed, at least selected part or parts or the whole of the rear-and-bottom structure being of a sheet of metal capable of providing a shielding effect. With this arrangement the rear plate of the rear-and-bottom structure is behind the cylinder unit and the connectors and conductors connecting the cylinder unit to the associated signal processing circuit. Thus, the rear metal sheet can prevent the invasion of exterior noise signals into the cabinet. The whole of the rear-and-bottom structure is of a sheet of metal. No extra shield pate, therefore, is required. When occasions demand, the rear-and-bottom structure may have resin plates press-fitted in openings made in its rear plate for the purpose.
The rear-and-bottom structure may have hooks stamped out and raised from the bottom. The hooks can be caught by notches formed in the chassis of the deck, thereby putting the hooks in contact with the chassis. The hook may have take any shape so far as it has a resilience strong enough to allow the hook to apply a resilient force to the chassis, thereby assuring that the hook be put in contact with the chassis.
Specifically such hook may have an oblique end bent relative to its upright rise from the bottom of the rear-and-bottom structure, allowing the oblique end to be yieldingly bent by inserting in the notch formed in the chassis of the deck when the rear-and-bottom structure is fixed to the chassis of the deck.